The effects of type and amounts of aggregate and cumulate state of particles on rheological properties of calcined gypsum from phosphogypsum slurry were studied by Brookfield soft solid rheometer(RST SST). And the data were fitted by the Herschel Bulkley model. The results show that there is an inflection point in the rheological curve when shear rate increases. The degree of shear thickening of the slurries in two sides of inflection point is different. There is no effect of type of aggregates on the rheological parameters of the slurry. The rheological parameters of the calcined gypsum from phosphogypsum slurry are affected by cumulated state of particles. And yield stress is more susceptible to cumulated state of particles than critical shear rate and rheological index. The rheological parameters of calcined gypsum from phosphogypsum slurries are higher than those of calcined gypsum from phosphogypsum paste when the amount of aggregate is 5%10%(by mass). But the results are opposite when the amount of aggregate is 10%40%.